This invention relates to a sheet folding machine.
In a sheet folding machine known in the art, as shown in FIG. 1, a knife b and a pair of sheet folding rollers c and c are disposed, respectively above and below a sheet conveying path a. A stopper d is provided along the sheet conveying direction of the sheet conveying path a. A sheet A conveyed along the conveying path a is positioned by abutting it against the stopper d with a sheet widthwise displacing mechanism (for displacing a sheet in its widthwise direction). Under this condition, the sheet A is temporarily folded in two with the knife b, and is then inserted into the nipping region c' of the sheet folding rollers c, whereby the sheet A is completely folded in two. The sheet A abuts against the stopper d by the sheet widthwise displacing mechanism so that a sheet is folded in two at the same position at all times.
The above-described arrangement of the prior art sheet folding mechanism requires independent sheet conveying, widthwise displacing and folding operations, and therefore folding sheets takes a relatively long period of time, i.e., the work efficiency is relatively low.
Also, since the provision of the sheet widthwise displacing mechanism is necessary, the conventional sheet folding machine suffers from high manufacturing cost.